The present invention relates to the field of 3GPP (Third Generation Partnership Project) Long Term Evolution/System Architecture Evolution (LTE/SAE). In particular, the invention relates to generation of keys such as Ciphering Keys (CKs) and Integrity protection Keys (IKs) in 3GPP LTE/SAE.
3GPP LTE/SAE requires separate keys used for AS (Access Stratum), NAS (Non-Access Stratum), and U-plane (User-plane) protection.
In UMTS (Universal Mobile Telecommunication System) a security mechanism is provided using an AKA (Authentication and Key Agreement) protocol based on a ‘challenge-response’ strategy, in which a ciphering key and an integrity protection key are obtained using a random value RAND.